EQ’s a little bit more complicated. There’s something called the dispersion effect, where over distance, high frequencies damp out faster than lower frequencies, except for in very interesting and weird acoustic environments, but for the most part, we’re going to lose more high end over distance, and so if we have things that are generally EQ’d to be darker, they will also appear further away, and things that are very bright are going to appear close.

The last one is going to be reverb. Reverb is sort of complicated, but reverb is the illustration of sound inside of a space, and where you locate that space comes down to a number of different settings, and they are: the level of early reflections, the level of late reflections, and the predelay.

And everything sort of plays into it, like the absorption qualities that your individual reverb unit allows you to setup, and things like this, that, and the other, but these are the three main ones.

So, early reflections. Early reflections are the first-order echoes that happen in a reverberant space, so when I speak, the sound waves go out, they hit a boundary, and they bounce back. That’s the early reflections.

The late reflections are my voice goes out, hits a boundary, reflects, hits another boundary, reflects, hits another, and it bounces around this room forming all of these complex reflections. Those are our late reflections. When we are closer to a source, we generally hear a greater proportion of the early reflections, and a smaller proportion of the late reflections, and conversely, the opposite is true. When we’re further away, we hear more of the late reflections and less of the early reflections, and they seem to blend together more, and it makes sense if you think about that.

You get more of a “boom, slap” type of thing if we’re close to something, and you get more of a convolution of echoes coming together when you’re farther away.

The other thing that happens is the predelay. If I’m very close to a source, you don’t hear any reverberation until that sound travels out, and bounces back, and at about a foot per millisecond, if I’m say, five feet away from my nearest boundary, then I’ll have about a ten second predelay before my first reflections get back to this microphone.

However, if I’m on the other side of the room, the first reflection that say, hits the floor and then bounces back up into the mic is going to get there almost at the exact same time as the actual direct sound of my voice.

So, as we get farther away, predelay goes down. When we’re very close, predelay goes up. All of these things come together, and we formulate a system of creating an idea of depth by using all of those processes.

So, what I’m going to do now is I’m going to play – I just said a random phrase that came to mind, I don’t know where it came from or – I just plucked it out of thin air, but I recorded myself saying a random phrase, and we’re going to do some experiments using processes to show depth of field.

Alright, so first of all, let me give you just basically the dry phrase here. Again, this is totally random.

[vocal playback]

I don’t know where I got that idea from. Anyway! What I have here setup is a number of the exact same recordings, but I’ve made a few modifications. I’ve set them up to a couple of different reverb units, and I’ve also set the EQ on my voice differently for each one. I’ve also set the level a little different. So, I’m going to show you a big contrast first.

Ready? Here we go.

[vocals]

Okay, it’s pretty obvious that one of those sounds closer, and one of those sounds further away. So, what all goes into that? Is it simply that there’s more reverb on one, and less reverb on another? Well, level of reverb does have a lot to do with it, but no, it’s not quite that simple.

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So, here’s what’s going on. First of all, the second one is four decibels quieter, and the amount of reverb is about seven decibels louder. So, it’s a much quieter dry signal, and a much louder signal being sent to the reverb, so I guess it only ends up being about 3dB louder, but I mean, the point still stands.

The EQ curve is a little different. Here, my EQ curve, I have a nice little top end boost and some presence boost and a little bit of a mid-range scoop, and on the second one, no treble or mid-range boost at all.

And then, lastly, the settings on my reverb are different. Here, I have this going to my near reverb. So, I’m using a medium sized hall, and I have a 72 millisecond predelay. That’s a pretty long predelay.

Also, my early reflections are very up, whereas my late reflections are about 13dB down.

Here, on my far reverb, I have a zero millisecond predelay, I have the early reflections turned down 8dB, and I have the late reflections up at zero dB. So, one more time.

[vocals]

Now, to illustrate the in between points, I’ve also decided to setup a couple other ones.

So, here I’m going to have a mid-field one, which is being sent to a reverb where it’s got a 26 millisecond predelay. So, a little less than halfway between the two extremes, and the late reflections and early reflections are set exactly even at minus five, and the level that’s going to them is minus nine, so it’s a little bit less than the far reverberant one, but it’s much more than the near reverberant one, and the EQ setting has a little bit of an upper mid-range bump, and a little bit of a high end bump, and the overall level is turned down slightly, but not as much as the far reverb one.

Then lastly, I’m going to have this super close one, where the amount – it’s going to the near reverb again, but this time it’s 18dB down, and the level of the signal is slightly turned up. It’s got a little bit more high end, it’s got a little bit more upper-mid, and it’s got about half a dB more overall level.

So, now I’m going to play them all, and you will hear the sound of it getting closer and closer as we go.

[male vocals]

Alright, so it’s creating the illusion of a front to back space, and I can iron that out more, like if I were to go in here and actually shelf off some top end… Maybe starting at around 5kHz, I’ll take out about 3 dB, then it’s really going to start to sound far away.

[vocals]

Right? So, using those different tools, you can create front to back image. What’s important to understand is that if you want to create the idea of something being very far away, it really helps to create the idea of something being very close.

So, if I were to play this…

[vocals]

…and then play this…

[vocals]

We get a very big sense of difference. There’s a large contrast between the two, and that creates a more pronounced front to back image overall.

Matthew Weiss

Matthew Weiss is the recordist and mixer for multi-platinum artist Akon, and boasts a Grammy nomination for Jazz & Spellemann Award for Best Rock album. Matthew has mixed for a host of star musicians including Akon, SisQo, Ozuna, Sonny Digital, Uri Caine, Dizzee Rascal, Arrested Development and 9th Wonder. Get in touch: Weiss-Sound.com